var a = [];
a.push(12)
console.log(a);
console.log([].push(4))
// console.log(b)
function A () {

}
const f = new A()
console.log(A.constructor.name)
console.log(A.prototype.constructor.name)
console.log(f instanceof A)
console.log(Object.getPrototypeOf(A).constructor.name)
console.log(A instanceof Function)
console.log(A instanceof Object)
